As they reach the next island, Ash & Co. meet up with Alexa, a journalist from the Kalos region, and her Pokémon Gogoat and Helioptile which don't register on Ash's Pokédex. Alexa explains that she's in the Decolora Islands to research an article on the tradition of the island, the Harvest Festival. As they enter the festival, they learn of a special Pokémon Sumo tournament where the winner shall win the Focus Band, and some rare berries. Ash, Cilan and Iris each decide to enter this tournament, but things turn out to be tougher than they thought. Who will win the tournament?

Heading to the next island, Alexa informs Ash & Co. that there are rumours of a hidden treasure on a nearby uninhabited island. Ash & co. decide to investigate this to try and find the treasure, helping Alexa to solve the mystery she learned when doing a report years before. However, Team Rocket have heard about the treasure as well and head there, and to top it off, the wild Pokémon on the island are intent on protecting it. Will Ash & Co. find it?